PLATE VI. 
Figs. 1-4. Halecium dichotomum (p. 13). 
Fig. 1. — A colony; natural size. 
Fig. 2. — A portion of a colony; magnified 15 diameters. 
Fig. 3. — Two consecutive liydropliores ; magnified about 20 diameters. 
Fig. 4. — Ovum with germinal vesicle and spot ; magnified 30 diameters. 
